Measuring and controlling take-up ratio of paper



March 31, 1964 EARLY 3,127,292

TAKE- R. MEASURING AND CONTROLLING RATIO OF PAPER IN PRODUCTION OF CORRUG D BOARD Filed Sept. 22, 1961 5 Sheets-Sheet 1 IN VEN TOR.

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March 31, 1964 R. EARLY 3,127,292 MEASURING AND CONTROLLING TAKE-UP RATIO OF PAPER IN PRODUCTION OF CORRUGATED BOARD Filed Sept. 22. 1961 r 3 Sheets-Sheet 2 false/r) 45 5516770! JZA/rws 52 as l l I42 1.44 7a 32- as m v INVENTOR.

March 3l, 1964 R.,L. EARLY 3,127,292

MEASURING AND CONTROLLING TAKE-UP RATIO OF PAPER IN PRODUCTION OF CORRUGATED BOARD Filed Sept. 22, 1961 3 Sheets-Sheet 3 I I I 1 s :3, k J INVENTOR.. 1 20/420 2. 6,22) QY Y p Q1 m4. JeLmL 47-70 tA/(PI United States Patent 3,127,292 MEASURING AND CONTROLLING TAKE-UP RATIO OF PAPER IN PRQDUCTION OF CORRUGATED BOARD Richard L. Early, Toledo, Ohio, assignor to Owens- Illinois Glass Company, a corporation of Ohio Filed Sept. 22, 1961, Ser. No. 140,041 8 Claims. (Cl. 15664) The invention relates to control over plural tnaveling webs of paper fed into a paper corrugating machine for forming a fluted web and adhesively combining with it one or more facing or liner webs to manufacture a web of corrugated board. More specifically, the invention pertains to a manner of maintaining a preselected ratio of the paper web going to make up the fluted web with respect to the liner Web that is applied to it.

In the manufacture of corrugated board, the ratio of the length of paper that is used in the flutes to the length of the paper that is used in the liner facing is ideally a critical natio yielding a composite board of maximum strength. This ratio is known in the trade as take-up ratio comparing the linear length of the two webs. If the take-up ratio is below the ideal value, the flutes will be distended so that the formed board is weakened and it thus possesses less than desired maximum strength. If the take-up ratio is above the ideal value, the strength of the board will be no greater than for the ideal ratio. Consequently, the additional paper used in the fluted web represents an unnecessary use or a costly waste of paper.

In present practice, a flute configuration known in the industry as a C flute board has an ideal take-up ratio of 1.43:1.

Thus far, measurements of take-up ratio in production machines have been made by crude spot checks using hand tachometers reading lineal footage of the paper I supply as each of the webs are fed to the machine.

Also, take-up ratio has been determined by stripping the formed corrugated board apart and measuring the length of the flute or corrugating medium per lineal unit measure of board. Obviously, the time lag in determining whether the corrugating machinery is functioning at the desired take-up ratio allows for appreciable error in production before a faulty ratio can be corrected.

It is, therefore, an object of the present invention to provide a simple yet effective means of continuously measuring the medium-to-liner ratio, or take-up ratio of the webs fed to the corrugating machinery and to control the feed of these paper webs to hold the take-up ratio thereof at a desired value.

Another object of the invention is to effect a considerable saving in paper in the production of suitable cor- 1 rugated board by instantaneously measuring and cont-rolling at a desired value the. ratio of the corrugating medium paper to the liner paper that is going continuously into the production of the corrugated paperboard.

A further object of the invention is to provide a continuous, accurate measurement of the take-up ratio on a corrugating machine by producing an electrical signal corresponding to the take-up ratio and recording or con trolling the take-up ratio on the machine in response to that signal.

Still another object of the invention is to provide an automatic control system for maintaining the take-up ratio on a corrugating machine at a desired level regardless of operating speed of the machine or size of the supply source for either the corrugating medium or liner paper.

The specific nature of this invention, as well as other objects and advantages thereof, will become apparent to those skilled in the art from the following detailed description, taken in conjunction with the annexed sheets ice of drawings, on which, by way of preferred example only, are illustrated two embodiments of this invention.

In the drawings:

FIG. 1 is essentially a perspective diagrammatic View of the roll stands of paper supply on a corrugating machine, and includes illustration of the invention, wherein separate generators are operated in response to traveling movement of the paper webs which convert their lineal speeds into corresponding separate electrical currents.

FIG. 2 is an electricm diagram of the control components, illustrating one form of the invention.

FIG. 3 is an electrical diagram of the ratio recording components illustrating a second form of the invention.

MG. 4 is in part a sectional front view of a roll-stand for a roll of corrugating medium paper and in part a schematic view of the invention as it is used in connection with the corrugating machine, illustrated on FIG. 1.

FIG. 5 is a sectional end view of the brake mechanism of the paper roll stand, as taken at line 5-5 on FIG. 4.

Referring to FIG. 1, a running web it of a paper, hereinafter referred to as corr-ugating medium, is caused to pass from a roll thereof on roll-stand 11 upwardly around a series of parallel guide rolls 12, 13, 14 and 15 and between the bite of a pair of corrugating rolls 16, 1?. In its passage between the corrugat-ing rolls 1'6, 17, the paper 10 is formed into a corrugated web which is thereafter bonded with an adhesively treated paper line-r web 18. This web is furnished from a roll of liner paper on a roll stand 19 and is passed over parallel guide rolls 20*, 2 1 and 242, then between a feed roll :23 and the corrugating roll 17. In its passage between corrugating rolls i6 and *17, the c'orru'gating medium 10 is fluted forming the corrugated web which is thereafter adhesively treated and bonded with the liner web 18. The formed -assembly it 18 is fed by feed rollers 24 and 25 from the machine, as in the case of a single-fa'cer machine. This assembly 1t 18 is a product known as single-face, corrugated board. If double-backed, corrugated board is to be produced, the single-face corrugated board 16, 18 is fed to a double-b acker machine (not shown) whereat a liner facing of paper, similar to liner web 1%, is adhesively bonded to the face of corrugated web it) opposite the surface bearing the first adhesively bonded liner web '15.

One of the corrugating rolls, such as roll 17, is drivably connected to the machine main drive (not shown) through its shaft 2 6. This shaft as is driven in synchronism with the other rolls on the machine and represents, as an element of reference, the machine speed. Shaft 26 has a gear 27 thereon which is in mesh with a pinion 23 on the shaft of a first generator Z9 suitably mounted in fixed position on the machine. The speed of the gear and pinion drive connection 2.7, 28 corresponds to the linear speed of the liner web 1 3 as it passes through the machine. Thus, generator 29 is effectively driven as a function of the speed of liner web 318. This generator may be driven suitably by a connection with any one of the shafts of rollers associated with the liner web or may be driven by a friction roller running on the surface of liner web .18. 'It is desired to drive this generator from a machine shaft that is driven from the main machine drive so that any error due to slippage between the other rolls and the liner web 13 may be avoided. At any rate, generator 29 is being driven to produce an electrical output that is proportional to the linear footage per minute of liner web 13 that is being used by the corrugating machine.

A second generator 30 has a roller 31 that is frictionally driven by riding on the eorrugating medium web iii. The electrical output of generator 36 is proportional to the linear footage per minute of corrugating medium that is being used by the machine.

The respective electrical outputs of generators 29 and 3t) are connected by lead wires 32 and 33 to the control unit, indicated generally at 34, to be presently described.

The control unit 34- (shown diagrammatically on FIGS. 2-4) is connected by conductors in conduit 35 to a re versible motor 36. The motor, in turn, is coupled through a geared reduction unit 33 to a hydraulic pressure regulator 37 supplying the hydraulic brake cylinder. The brake regulator 37 is connected to supply hydraulic fluid pressure to brake cylinder 39 by pipe 40.

The roll stand 11 for the corrugating medium web 19 is comprised of a frame 41 having upstanding arm castings 42. A shaft 43 rotatably holding the supply roll of corrugating medium paper 1% is bearing mounted on the castings 42. The one end of shaft 43 is provided with a brake drum 44. A pair of brake shoes 45 are mounted internally of the drum 44 and supported on the brake housing 46 on the arm casting 42. The brake shoes 45 are pivoted at pin 47 and are normally urged away from the drum 44 by spring 43. The brake cylinder 39 is double-acting and connected to the brake shoes 45 by piston rods 49.

As shown on FIG. 1, the roll stand 19 for paper web 18 is similarly constructed having a frame 50, upstanding arm castings 51 and a rotatable central shaft (not shown) supporting a supply roll of the liner paper. A brake assembly 52, similar to that just described, is operable for braking rotation of the central shaft and is connected by a pipe 53 to a hydraulic pressure regulator 54. This regulator 54 is controlled manually at rotatable knob 55 which regulates the braking force or the friction on the central shaft of roll stand 19. Thus, the brake may be regulated as desired for maintaining satisfactory tension in the supply of paper liner web 13 from the roll thereof on roll stand 19. This requires keeping web 18 taut and free of wrinkles or tears as it passes over the rollers 20, 21, 22 and 23 and is adhesively treated and fed onto the face of the formed corrugated web 10.

Hydraulic fluid for both brake assemblies is supplied from a sump 56 connected to a pump 57 which is in turn connected to regulator 37 by pipe 58 and regulator 54 by pipe 59.

Referring now to FIGS. 2 and 4, the take-up ratio control of this invention will now be described.

The generator 30 is driven by roller 31 running on the corrugating medium web 10 and its voltage output is di rectly proportional to the feet per minute of web It being used. The generators 29 and 36 are electrically connected to a control circuit 59 which is connected to a polarity sensitive motor control. The leads 33 of generator 30 are connected across the end terminals of a potentiometer 60. This voltage is distributed linearly along the length of potentiometer 6i). Generator 29 is driven by a shaft of the corrugating machine, which is running at a speed proportional to the liner being used. Generator 29 has its output leads 32 connected to slide 61 and to the end of potentiometer 61 through a resistor 63. The slide 61 of potentiometer 60 is set at a proportional length of the potentiometer to obtain the ratio of voltages that corresponds to the desired take-up ratio. The potentiometer 60 is provided with a scale 62 calibrated for a range of take-up ratio at which the control (slide 61) may be set. As an elementary example, slider 61 may be set at onethird of the linear distance along potentiometer 60. Thus, when generator 29 is generating two-thirds the voltage output of generator 30, no current will flow in resistor 63 and no voltage drop will appear across this resistor. This will correspond to a take-up ratio of 1.5:1. As a means of reading the take-up ratio on the machine, a volt meter 6 is connected in parallel with resistor 63. Slide 61 may be adjusted until the volt meter reads zero. This will indicate the take-up ratio by a reading of slider position with respect to scale 62. A circuit 65 to the d polarity sensitive switch 66 has a line switch 67. Thus, the take-up ratio on the machine may be determined by opening switch 67 and adjusting slide 61 on scale 62 to obtain a zero reading on volt meter 64.

The polarity sensitive switch 66, may be an electronic unit or polarity sensitive relays. One example of electronic unit of this type is a General Electric Electronic Positioning Control, CR 7510-A102, such as described in the GE printed bulletin GEI-31257D. The polarity sensitive switch is wired from an electrical supply at L and L to control the reversible operation of motor 36. With line switch 67 closed, any current flow in resistor 63 would operate the polarity sensitive switch 66 to operate reversible motor 36 to either increase or decrease brake tension on the roll stand 11, earlier described.

In operation, the desired take-up ratio may be set at slider 61 on scale 62. This is preferably a 1.43:1 ratio, as stated earlier, for desired operation of the corrugating machine. Using D.C. generators at 29 and 30, the current output of each so long as the machine is operating at the selected take-up ratio will result in zero current flow in resistor 63, and, of course, zero current flow in the polarity sensitive switch 66. This will retain the motor 36 de-energized and the brake setting on roll stand 11 will be unchanged. If the take-up ratio begins to increase on the machine, generator 30 will speed up in relation to generator 29 and current will flow in the clockwise direction in the circuit 32 and through resistor 63 for polarities shown on FIGS. 2 and 3. This current will also appear in the polarity sensitive switch 66 and it will, in turn, operate the motor 36 to increase the hydraulic fluid pressure at the hydraulic regulator 37. This will increase the braking force on web 10 through an increase of braking pressure of brake 45 on the brake drum 44. On the other hand, if generator 30 reduces its speed in relation to generator 29, which corresponds to a reduction in the take-up ratio on the machine, current will flow in a counter clockwise direction in the circuit 32 and resistor 63 in accordance with polarities shown on FIGS. 2 and 3. This current flow will cause the polarity sensitive switch 66 to operate motor 36 in the direction to reduce the braking force on web 10 at the roll stand 11. When the ratio is restored to the selected value, the current flow in elements 63 and 66 will go to zero and motor 36 will stop. No further adjustment will occur until a further change in the take-up ratio occurs. Thus, the take-up ratio on the machine is automatically maintained at a desired preselected ratio.

The system can be designed to operate with either D.C. (as illustrated) or AC. generators whose outputs have been converted to D.C. by rectification and filtering. The reversible motor 36 may be either single-phase (as illustrated), two-phase or three-phase.

Having described one embodiment of the invention providing fully automatic take-up ratio control on a corr-ugating machine, the second embodiment of the invention, as shown on FIG. 3, will now be described. This system provides for either indicating or recording takeup ratios of the machine, or both. The web 10 of corrugating medium paper drives a roller 31 of generator 30', and generator 29 is driven by a shaft of the machine corresponding to the linear travel of the Web 1 8 of liner paper, as earlier described herein. These generator outputs are connected to the potentiometer 60; as described before, and a resistor 63' is connected in circuit with wire 32. An instrument 70 is connected across resistor 63 and is calibrated to indicate the take-up ratio. In the example illustrated on FIG. 2, the instrument 70 is a galvanometer-type instrument which has its zero or center point calibrated for the desired take-up ratio (e.g. 1.43:1). Thus, as current flows in resistor 63 in either direction, the instrument 70 will respond proportionally to indicate the take-up ratio reading instantly and as it is occurring on the corrugating machine.

As a further variation, the instrument 70 may take the form of a known recorder instrument properly calibrated to indicate and record the history of the take-up ratio of the machine. A suitable recording instrument will convert the current in resistor 63 into an accurate ratio and record this ratio continuously as a function of time of machine operation. Thus, the invention not only provides an automatic take-up ratio control, but also provides an accurate and continuous indication of said ratio giving a permanent record of machine production performance. An example of a commercially available recorder for this purpose is the Single Point Recorder, Model 6701, of Daystrom-Weston Instruments, as described in their printed publication E-l029, copyrighted 1959.

In considering the two above-described embodiments of the invention, they may be employed alternatively on a corrugating machine or they may be combined. If the last described embodiment of FIG. 3 is employed singly on a machine, the brake adjustment for roll stand '11 will, of course, be made manually by an operator in a manner similar to the brake adjustment means (knob 55) on roll stand 19 to maintain a desired take-up ratio. On the other hand, in utilizing the second embodiment, the indicating and recording instrument 70* may be connected across resistor 63 and in parallel with the polarity sensitive switch 66 of FIG. 2. In this case, the take-up ratio of the machine would be automatically regulated and maintained at the desired preselected value, and an instant-aneous record of the take-up ratio would be available.

While two embodiments of the present invention have been herein specifically described, other embodiments and variations may occur to those skilled in the art after a knowledge of the disclosure herein, and it is desired to include within the scope of the patent granted hereon all such embodiments and variations, and more particularly as comprehended by the appended claims.

I claim:

1. In a corrugating machine including a set of corrugating rolls, gluing rolls and liner rolls wherein a corrugating medium and a liner paper are fed through said rolls, the improvement for maintaining the ratio of corr-ugating-medium paper to liner-medium paper at a preselected value comprising a supply stand for supporting a roll of corrugated-medium, a fluid-operated brake controlling the tension on the supply of said corrugated-medium paper, a first electrical generator, drive means for said generator operated in response to linear travel of said corrugated-medium paper, a second electrical generator, drive means for said second generator operating in response to the linear travel of said liner paper, a control circuit including means -for producing a current corresponding to the ratio of voltages generated by said first generator compared to said second generator, a means connected to operate said brake, thereby regulating the tension on said corrugatedmediurn paper, and a control means in said circuit and operated in response to said current for increasing brake tension by an increase in said ratio of voltages and decreasing brake tension by a decrease in said ratio of voltages.

2. In a corrugating machine including a set of corrugating rolls, gluing rolls and liner rolls wherein a corrugating medium and a liner medium are fed through said rolls, a supply stand for supporting a roll of corrugatingmedium paper, a supply stand for supporting a roll of liner paper independently of said roll of corrugating-medium, a brake controlling the tension on the supply of said corrugating-medium paper, a first electrical generator, drive means for said generator operated in response to linear travel of said corrugating-medium paper, a second electrical generator, drive means for said second generator operating in response to the linear travel of said liner paper, a circuit connected to said first and second generators for receiving their output voltages, and means in said circuit and operated in response to said output voltages for regulating said brake tension as a function of the ratio of said output voltages of said generators.

3. In a corrugating machine including a set of corrugating rolls, gluing rolls and liner rolls wherein a corrugating medium and a liner medium are fed through said rolls, the improvement for maintaining a preselected ratio of corrugating-medium to liner paper ratio comprising a supply stand for supporting a roll of corrugating-medium paper, a supply stand for supporting a roll of liner paper independently of said roll of corrugating-medium, a fluid-operated brake controlling the tension on the supply of said corrugatingmedium paper, a first electrical generator, drive means for said generator operated in response to linear travel of said corrugating-medium paper, a second electrical generator, drive means for said second generator operating in response to the linear travel of said liner paper, a control circuit including means for producing a current output corresponding to the ratio of corrugated medium paper travel to liner paper travel, a reversible electric motor connected to operate said brake, thereby regulating the supply of said corrugating-rnedium paper, and a motor control means in said circuit and operated in response to said current for automatically maintaining the said ratio at the preselected value by changing brake tension upon a deviation in said current from a value corresponding to said preselected ratio.

4. The machine of claim 3, wherein said motor control means includes a polarity-sensitive switch connected to said control circuit.

5. The machine of claim 3, wherein said means for producing a current corresponding to said ratio of generated voltages comprises a resistance connected in circuit with said first generator and a second resistance connected in parallel with said first resistance and in series circuit with said second generator such that the generated currents are opposing, and a polarity sensitive position control connected across said second resistance, said position control being connected to said reversible motor and operated responsive to the combined generator outputs.

6. In a corrugating machine including a set of corrugating rolls, gluing rolls and liner rolls wherein a corrugating medium and a liner paper are fed through said rolls, the improvement for maintaining the ratio of corrugatingmedium paper to liner-'nedium paper at a preselected value comprising a supply stand for supporting a roll of corrugating-medium paper, a supply stand for supporting a roll of liner paper independently of said roll of corrugating-mediurn, a fluid-operated brake controlling the tension on the supply of said corrugating-medium paper, a first electrical generator, drive means for said generator operated in response to linear travel of said corrugatingmedium paper, a second electrical generator, drive means for said second generator operating in response to the linear travel of said liner paper, a control circuit connected to said first and second generators including means for producing a current corresponding to the operating ratio of corrugating-medium to liner paper, a means connected to operate said brake, thereby regulating the tension on said corrugating-medium paper, and a control means in said circuit and operated in response to said current for automatically adjusting the brake to maintain the corrugating-medium to liner-medium ratio at said preselected value by increasing brake tension in response to increase in said medium-to-liner ratio and decrease brake tension in response to a decrease in said mediumto-liner ratio.

7. A method for controlling the ratio of the liner paper to medium paper at a preselected value in a corrugated paper web as it is being continuously produced on a machine comprising moving a web of medium paper toward and through a corrugator device to work said paper into corrugated form, moving a web of liner paper into surface contact with said corrugated form and ad hesively securing the two to form a corrugated web, generating a first voltage in response to the rate of movement of the medium paper, generating a second voltage in response to the rate of movement of the liner paper,

combining said first and second voltages to produce a third voltage that is equal to the ratio of the speed of the medium paper to the liner paper, and automatically controlling the rate of movement of the medium paper in response to said third voltage by a braking action applied so that the medium paper rate is maintained at said preselected ratio with respect to the liner paper rate.

8. In a corrugating machine continuously forming a web of a paper medium into corrugated form and uniting it With a continuous Web of liner paper to form a corrugated Web, the improvement comprising a first generator means operated to produce an electrical output corresponding to the linear speed of said medium web, second generator means operated to produce an electrical output corresponding to the linear speed of said liner web, means connected in circuit with said first and second generator means to produce a third electrical output corresponding to a ratio of said first generator output to said second generator output, and means connected to said last-named means and operated in response to said third til electrical output comprising a brake device, means connecting the brake device to regulate the rate of movement of the web of the paper medium, a control connected to the brake device for increasing or decreasing its braking force, a reversible electric motor connected to operate said brake control, and a polarity sensitive switch device connected to said motor for controlling the latter, said polarity sensitive switch device being connected to receive said third electrical output, said device operating the motor to increase the braking force whenever said third output indicates a medium-to-liner ratio either greater or less than a preselected medium-to-liner ratio.

References Cited in the file of this patent UNITED STATES PATENTS 2,248,504 Kenny July 8, 1941 2,375,451 Waters May 8, 1945 2,482,627 Langston Sept. 20, 1949 3,029,022 Horvath et a1. Apr. 10, 1962 

1. IN A CORRUGATING MACHINE INCLUDING A SET OF CORRUGATING ROOLS, GLUING ROLLS AND LINER ROLLS WHEREIN A CORRUGATING MEDIUM AND A LINER PAPER WE FED THROUGH SAID ROLLS, THE IMPROVEMENT FOR MAINTAINING THE RATIO OF CORRUGATING-MEDIUM PAPER TO LINER-MEDIUM PAPER AT A PRESELECTED VALUE COMPRISING A SUPPLY STAND FOR SUPPORTING A ROLL OF CORRUGATED-MEDIUM, A FLUID-OPERATED BRAKE CONTROLLING THE TENSION ON THE SUPPLY OF SAID CORRUGATED-MEDIUM PAPER, A FIRST ELECTRICAL GENERATOR, DRIVE MEANS FOR SAID GENERATOR OPERATED IN RESPONSE TO LINEAR TRAVEL OF SAID CORRUGATED-MEDIUM PAPER, A SECOND ELECTRICAL GENERATOR, DRIVE MEANS, FOR SAID SECOND GENERATOR OPERATING IN RESPONSE TO THE LINEAR TRAVEL OF SAID LINER PAPER, A CONTROL CIRCUIT INCLUDING MEANS FOR PRODUCING A CURRENT CORRESPONDING TO THE RATIO OF VOLTAGES GENERATED BY SAID FIRST GENERATOR COMPARED TO SAID SECOND GENERATOR, A MEANS CONNECTED TO OPERATE SAID BRAKE, THEREBY REGULATING THE TENSION ON SAID CORRUGATED-MEDIUM PAPER AND A CONTROL MEANS IN SAID CIRCUIT AND OPERATED IN RESPONSE TO SAID 